How I resolved it. its been a while but you can try this out.
First, tweak this or add to your capacitor.config.json
“SplashScreen”: {
  "launchShowDuration": 3000,
  "launchAutoHide": false,
  "androidScaleType": "CENTER_INSIDE",
  "splashFullScreen": false,
  "splashImmersive": false,
  "backgroundColor": "#1C3461",
  "androidSplashResourceName": "splash"
}
then use a setTimeout to hide the splash screen in your app.component.ts
 this.platform.ready().then(async () => {
     setTimeout(()=>{
        SplashScreen.hide({
          fadeOutDuration: 1000
        });
      }, 2000)
})
You may also need to change the launcher background and relevant styles to colour in android studio
android\app\src\main\res\values\ic_launcher_background.xml
android\app\src\main\res\values\styles.xml
Good luck.